As disclosed in US 2012/0048075 a machining apparatus has a frame and two generally parallel horizontal guides on the frame, one of which extends through at least one loading station and through at least one work station. A slide carrying a pair of spindles each capable of gripping a workpiece is shiftable between positions with the spindles aligned with the stations. A tool holder is shiftable on the other of the guides toward and away from the work station. Respective guides between each of the spindles and the slide allow vertical movement of the spindles on the slide. Actuators shift the slide horizontally on the one guide, shift the tool holder horizontally parallel to the slide on the other guide, and shift the spindles vertically on the slide.
While one workpiece is machined in the first spindle, a completely machined workpiece can be replaced by an unmachined one in the second spindle. Both workpiece spindles can be moved together horizontally on the machine frame so as to be loaded alternately. The advancing motions are effected by vertically moving the workpiece spindles, and the tool turret is moved horizontally during the infeed action.